Oxford MIPAS meeting#74
26 Apr 05

Present

• Oxford: Anu Dudhia, Chris Hepplewhite, Chiara Piccolo, Gareth Thomas, Joanne Walker, Claire Waymark.
• RAL: Alison Waterfall

Instrument Status [Prev] [Next]

Some details on the Envisat Web-Site including Instrument Availability web-site

Latest version of Mission Planning Document (from Marta de Laurentis) covering 1 Jan 05 to 09 May 05:

• [MIPAS_Mission_Planning_2005_DRAFT.xls] (Excel spreadsheet)
• [MIPAS_Mission_Planning_2005_DRAFT.html] (Converted to Web page)

Currently in the middle of a 3-day period of operation in the new nominal mode (floating altitude offset).

• Note that in the current operating mode the instrument is automatically reset each orbit 200 seconds after the satellite crosses the equator northwards. This means a data gap of around 4 minutes each orbit, probably around 20degS.
• MIPAS "Monthly" report MIPAS_MR_20040326_20050228.pdf (by Roberta Mantovani) summarises all the developments with the instrument and data processing Mar04-Feb05.
• See today's email from Rob Koopman (ESA)

L1 Data [Prev] [Next]

[BADC Archive of reprocessed L1B Data]

• No change to reprocessed L1B stored at BADC since 18 Jan 05
• ESA about to start operational processing of L1B data acquired in reduced resolution mode.
• Roberta Mantovani (ESRIN) today distributed the first L1B data for the new nominal mode with floating altitudes (Orbit 15694 from 01 Mar 2005, with orbits 15695 and 15696 to follow).

L2 OFL Data [Prev] [Next]

[Plots of profile locations]

• v4.62 data recently received for 2004.

TES Comparisons (CW/CP) [Prev] [Next]

(CW) Looking at TES nadir spectra from 22 Aug 04 over the ocean

• Investigating optimum 3cm-1 microwindows for joint retrieval of surface temperature and atmospheric profiles of temperature, ozone and water vapour.

(CP) Looking at TES limb spectra: many corrupt spectra but at present limiting to using just central pixel (~16km) and attempting pT retrieval using MORSE

• Although 16km spectra looks "reasonable", still fails to produce a reasonable pT retrieval.

CO Retrieval (JW) [Prev] [Next]

Looking at MIPAS data for signatures of biomass burning in Africa on 11 Jul 03

• Orbit 7119 shows no obvious signal over the Atlantic, now looking at orbits over Africa itself.
• MOPITT web-site confirms that no obvious CO signature over the Atlantic

Microwindows for 0.0625cm-1 (AD) [Prev] [Next]

Currently selecting microwindows for new nominal mode operations which employ floating altitude grid (lowest altitude 3-9km from pole-equator) and 1.5km spacing at lower altitudes

• LUTs for 5 pT microwindows now generated and delivered to IFAC.
• Microwindow selection for other species and LUT generation still in progress.

MIPAS Quality Working Group Meeting#7 (AD/CP) [Prev] [Next]

Held at IFAC, 18/19 Apr 2005

• L2 Minutes (from Simone Ceccherini, 02MAY05)
• Presentation (PDF File) from AD covering
  • comparison of new microwindows selected for 1.5km with those selected for Aug'04 data 3km spacing
  • Results of local (MORSE) retrieval applied to recently generated L1B data from Jan 2005.

Validation Papers [Prev] [Next]

Herb Fischer (IMK) is convening the first meeting of the MIPAS L2 validation group today in Vienna (linked to EGU conference).

TASTE Project (CW) [Prev]

"Technical ASsistance To Envisat validation by soundings, spectrometers and radiometers"

• Recently circulated report TASTE_Update_Report_0503a.pdf "Correlative Database Status and Validation Highlights March 2005"
• Updated list of correlative measurements available to March 2005

Aura/HiRDLS (CH) [Next]

Main effort at the moment is to validate the L1, ie produce calibrated radiances.

• Cannot view on board black body so relying on pre-launch testing and external radiances.
• Hoping to use MIPAS where views coincide (HiRDLS operating routinely since end of January 2005) for radiance validation, and eventually MIPAS retrievals for L2 validation.

NO2 Retrievals (AD) [Next]

A `feature' has been noticed in our retrievals of NO2 from orbits 15237-15239 (29 Jan 05): both day and night parts of orbit have a sharp dip in NO2 values at high altitude with +/- 5 deg of the equator [Plots]

• Occurs at same latitude in tangent point rather than satellite position in orbit, so not likely to be a satellite/instrument artefact
• No equivalent feature in H2O retrieval, so unlikely to be a real atmospheric phenomenon or calibration problem with Band C
• Most likely explanation is that it is a local problem with our NO2 retrieval, eg due to interpolation of IG atmospheres.

HNO3 Retrievals (CP) [Next]

IFAC have been investigating impact of updated HNO3 line parameters but notice a larger discrepancy (~4% in peak HNO3) between their retrievals using a line-by-line model and the HNO3 LUTs than between the two sets of line parameters.

• Oxford tests show much smaller (0.5%) difference using LUTs compared to our line-by-line model (which is that used to generate the LUTs)
• Main difference seems to be between the Oxford and IFAC line-by-line models. Currently checking whether same TIPS data is used.

Email from  Rob Koopman (ESA)  26 Apr 2005 
Subject: MIPAS Report: March 2004 - February 2005

Dear all,

The MIPAS instrument is performing remarkably well in its new experimental
mode.

Measurements are performed frequently (with a duty cycle of about 35%), and all
level 0 data are acquired and archived systematically.  The data processors and
their configuration are currently being adapted to the reduced spectral
resolution (40.99%) and to the increased vertical sampling.

Therefore the generation of the operational MIPAS performance reports has
recommenced.

The report in subject covers the entire interval since the interruption of the
operational MIPAS mission in March 2004.

It can be downloaded from:
http://earth.esa.int/pcs/envisat/mipas/reports/monthly/